Is DESCENDING valid? I can't test that where I am, but its not listed as a sort option in the mysql documentation. Assuming its not, attempting to query that would result in a sql syntax error and fail the query.
PHP wise you need to verify your resources before using them:
if ( $FDISTRIBUTOR = mysql_query( $SQLDISTRIBUTOR, $CON ))
// now you can do whatever
Note as well that the mysql library is deprecated and will be removed in a future version.